staging: comedi: fix oops for USB DAQ devices.
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / include / linux / percpu.h
blob9ca008f0c542935440f3c39c0a5fb070dd6f5e8c
1 #ifndef __LINUX_PERCPU_H
2 #define __LINUX_PERCPU_H
4 #include <linux/preempt.h>
5 #include <linux/smp.h>
6 #include <linux/cpumask.h>
7 #include <linux/pfn.h>
8 #include <linux/init.h>
10 #include <asm/percpu.h>
12 /* enough to cover all DEFINE_PER_CPUs in modules */
13 #ifdef CONFIG_MODULES
14 #define PERCPU_MODULE_RESERVE (8 << 10)
15 #else
16 #define PERCPU_MODULE_RESERVE 0
17 #endif
19 #ifndef PERCPU_ENOUGH_ROOM
20 #define PERCPU_ENOUGH_ROOM \
21 (ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES) + \
22 PERCPU_MODULE_RESERVE)
23 #endif
26 * Must be an lvalue. Since @var must be a simple identifier,
27 * we force a syntax error here if it isn't.
29 #define get_cpu_var(var) (*({ \
30 preempt_disable(); \
31 &__get_cpu_var(var); }))
34 * The weird & is necessary because sparse considers (void)(var) to be
35 * a direct dereference of percpu variable (var).
37 #define put_cpu_var(var) do { \
38 (void)&(var); \
39 preempt_enable(); \
40 } while (0)
42 #define get_cpu_ptr(var) ({ \
43 preempt_disable(); \
44 this_cpu_ptr(var); })
46 #define put_cpu_ptr(var) do { \
47 (void)(var); \
48 preempt_enable(); \
49 } while (0)
51 /* minimum unit size, also is the maximum supported allocation size */
52 #define PCPU_MIN_UNIT_SIZE PFN_ALIGN(32 << 10)
55 * Percpu allocator can serve percpu allocations before slab is
56 * initialized which allows slab to depend on the percpu allocator.
57 * The following two parameters decide how much resource to
58 * preallocate for this. Keep PERCPU_DYNAMIC_RESERVE equal to or
59 * larger than PERCPU_DYNAMIC_EARLY_SIZE.
61 #define PERCPU_DYNAMIC_EARLY_SLOTS 128
62 #define PERCPU_DYNAMIC_EARLY_SIZE (12 << 10)
65 * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy
66 * back on the first chunk for dynamic percpu allocation if arch is
67 * manually allocating and mapping it for faster access (as a part of
68 * large page mapping for example).
70 * The following values give between one and two pages of free space
71 * after typical minimal boot (2-way SMP, single disk and NIC) with
72 * both defconfig and a distro config on x86_64 and 32. More
73 * intelligent way to determine this would be nice.
75 #if BITS_PER_LONG > 32
76 #define PERCPU_DYNAMIC_RESERVE (20 << 10)
77 #else
78 #define PERCPU_DYNAMIC_RESERVE (12 << 10)
79 #endif
81 extern void *pcpu_base_addr;
82 extern const unsigned long *pcpu_unit_offsets;
84 struct pcpu_group_info {
85 int nr_units; /* aligned # of units */
86 unsigned long base_offset; /* base address offset */
87 unsigned int *cpu_map; /* unit->cpu map, empty
88 * entries contain NR_CPUS */
91 struct pcpu_alloc_info {
92 size_t static_size;
93 size_t reserved_size;
94 size_t dyn_size;
95 size_t unit_size;
96 size_t atom_size;
97 size_t alloc_size;
98 size_t __ai_size; /* internal, don't use */
99 int nr_groups; /* 0 if grouping unnecessary */
100 struct pcpu_group_info groups[];
103 enum pcpu_fc {
104 PCPU_FC_AUTO,
105 PCPU_FC_EMBED,
106 PCPU_FC_PAGE,
108 PCPU_FC_NR,
110 extern const char *pcpu_fc_names[PCPU_FC_NR];
112 extern enum pcpu_fc pcpu_chosen_fc;
114 typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
115 size_t align);
116 typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
117 typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
118 typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
120 extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
121 int nr_units);
122 extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
124 extern int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
125 void *base_addr);
127 #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
128 extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
129 size_t atom_size,
130 pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
131 pcpu_fc_alloc_fn_t alloc_fn,
132 pcpu_fc_free_fn_t free_fn);
133 #endif
135 #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
136 extern int __init pcpu_page_first_chunk(size_t reserved_size,
137 pcpu_fc_alloc_fn_t alloc_fn,
138 pcpu_fc_free_fn_t free_fn,
139 pcpu_fc_populate_pte_fn_t populate_pte_fn);
140 #endif
143 * Use this to get to a cpu's version of the per-cpu object
144 * dynamically allocated. Non-atomic access to the current CPU's
145 * version should probably be combined with get_cpu()/put_cpu().
147 #ifdef CONFIG_SMP
148 #define per_cpu_ptr(ptr, cpu) SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu)))
149 #else
150 #define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); VERIFY_PERCPU_PTR((ptr)); })
151 #endif
153 extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
154 extern bool is_kernel_percpu_address(unsigned long addr);
156 #if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
157 extern void __init setup_per_cpu_areas(void);
158 #endif
159 extern void __init percpu_init_late(void);
161 extern void __percpu *__alloc_percpu(size_t size, size_t align);
162 extern void free_percpu(void __percpu *__pdata);
163 extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
165 #define alloc_percpu(type) \
166 (typeof(type) __percpu *)__alloc_percpu(sizeof(type), __alignof__(type))
169 * Optional methods for optimized non-lvalue per-cpu variable access.
171 * @var can be a percpu variable or a field of it and its size should
172 * equal char, int or long. percpu_read() evaluates to a lvalue and
173 * all others to void.
175 * These operations are guaranteed to be atomic w.r.t. preemption.
176 * The generic versions use plain get/put_cpu_var(). Archs are
177 * encouraged to implement single-instruction alternatives which don't
178 * require preemption protection.
180 #ifndef percpu_read
181 # define percpu_read(var) \
182 ({ \
183 typeof(var) *pr_ptr__ = &(var); \
184 typeof(var) pr_ret__; \
185 pr_ret__ = get_cpu_var(*pr_ptr__); \
186 put_cpu_var(*pr_ptr__); \
187 pr_ret__; \
189 #endif
191 #define __percpu_generic_to_op(var, val, op) \
192 do { \
193 typeof(var) *pgto_ptr__ = &(var); \
194 get_cpu_var(*pgto_ptr__) op val; \
195 put_cpu_var(*pgto_ptr__); \
196 } while (0)
198 #ifndef percpu_write
199 # define percpu_write(var, val) __percpu_generic_to_op(var, (val), =)
200 #endif
202 #ifndef percpu_add
203 # define percpu_add(var, val) __percpu_generic_to_op(var, (val), +=)
204 #endif
206 #ifndef percpu_sub
207 # define percpu_sub(var, val) __percpu_generic_to_op(var, (val), -=)
208 #endif
210 #ifndef percpu_and
211 # define percpu_and(var, val) __percpu_generic_to_op(var, (val), &=)
212 #endif
214 #ifndef percpu_or
215 # define percpu_or(var, val) __percpu_generic_to_op(var, (val), |=)
216 #endif
218 #ifndef percpu_xor
219 # define percpu_xor(var, val) __percpu_generic_to_op(var, (val), ^=)
220 #endif
223 * Branching function to split up a function into a set of functions that
224 * are called for different scalar sizes of the objects handled.
227 extern void __bad_size_call_parameter(void);
229 #define __pcpu_size_call_return(stem, variable) \
230 ({ typeof(variable) pscr_ret__; \
231 __verify_pcpu_ptr(&(variable)); \
232 switch(sizeof(variable)) { \
233 case 1: pscr_ret__ = stem##1(variable);break; \
234 case 2: pscr_ret__ = stem##2(variable);break; \
235 case 4: pscr_ret__ = stem##4(variable);break; \
236 case 8: pscr_ret__ = stem##8(variable);break; \
237 default: \
238 __bad_size_call_parameter();break; \
240 pscr_ret__; \
243 #define __pcpu_size_call_return2(stem, variable, ...) \
244 ({ \
245 typeof(variable) pscr2_ret__; \
246 __verify_pcpu_ptr(&(variable)); \
247 switch(sizeof(variable)) { \
248 case 1: pscr2_ret__ = stem##1(variable, __VA_ARGS__); break; \
249 case 2: pscr2_ret__ = stem##2(variable, __VA_ARGS__); break; \
250 case 4: pscr2_ret__ = stem##4(variable, __VA_ARGS__); break; \
251 case 8: pscr2_ret__ = stem##8(variable, __VA_ARGS__); break; \
252 default: \
253 __bad_size_call_parameter(); break; \
255 pscr2_ret__; \
259 * Special handling for cmpxchg_double. cmpxchg_double is passed two
260 * percpu variables. The first has to be aligned to a double word
261 * boundary and the second has to follow directly thereafter.
262 * We enforce this on all architectures even if they don't support
263 * a double cmpxchg instruction, since it's a cheap requirement, and it
264 * avoids breaking the requirement for architectures with the instruction.
266 #define __pcpu_double_call_return_bool(stem, pcp1, pcp2, ...) \
267 ({ \
268 bool pdcrb_ret__; \
269 __verify_pcpu_ptr(&pcp1); \
270 BUILD_BUG_ON(sizeof(pcp1) != sizeof(pcp2)); \
271 VM_BUG_ON((unsigned long)(&pcp1) % (2 * sizeof(pcp1))); \
272 VM_BUG_ON((unsigned long)(&pcp2) != \
273 (unsigned long)(&pcp1) + sizeof(pcp1)); \
274 switch(sizeof(pcp1)) { \
275 case 1: pdcrb_ret__ = stem##1(pcp1, pcp2, __VA_ARGS__); break; \
276 case 2: pdcrb_ret__ = stem##2(pcp1, pcp2, __VA_ARGS__); break; \
277 case 4: pdcrb_ret__ = stem##4(pcp1, pcp2, __VA_ARGS__); break; \
278 case 8: pdcrb_ret__ = stem##8(pcp1, pcp2, __VA_ARGS__); break; \
279 default: \
280 __bad_size_call_parameter(); break; \
282 pdcrb_ret__; \
285 #define __pcpu_size_call(stem, variable, ...) \
286 do { \
287 __verify_pcpu_ptr(&(variable)); \
288 switch(sizeof(variable)) { \
289 case 1: stem##1(variable, __VA_ARGS__);break; \
290 case 2: stem##2(variable, __VA_ARGS__);break; \
291 case 4: stem##4(variable, __VA_ARGS__);break; \
292 case 8: stem##8(variable, __VA_ARGS__);break; \
293 default: \
294 __bad_size_call_parameter();break; \
296 } while (0)
299 * Optimized manipulation for memory allocated through the per cpu
300 * allocator or for addresses of per cpu variables.
302 * These operation guarantee exclusivity of access for other operations
303 * on the *same* processor. The assumption is that per cpu data is only
304 * accessed by a single processor instance (the current one).
306 * The first group is used for accesses that must be done in a
307 * preemption safe way since we know that the context is not preempt
308 * safe. Interrupts may occur. If the interrupt modifies the variable
309 * too then RMW actions will not be reliable.
311 * The arch code can provide optimized functions in two ways:
313 * 1. Override the function completely. F.e. define this_cpu_add().
314 * The arch must then ensure that the various scalar format passed
315 * are handled correctly.
317 * 2. Provide functions for certain scalar sizes. F.e. provide
318 * this_cpu_add_2() to provide per cpu atomic operations for 2 byte
319 * sized RMW actions. If arch code does not provide operations for
320 * a scalar size then the fallback in the generic code will be
321 * used.
324 #define _this_cpu_generic_read(pcp) \
325 ({ typeof(pcp) ret__; \
326 preempt_disable(); \
327 ret__ = *this_cpu_ptr(&(pcp)); \
328 preempt_enable(); \
329 ret__; \
332 #ifndef this_cpu_read
333 # ifndef this_cpu_read_1
334 # define this_cpu_read_1(pcp) _this_cpu_generic_read(pcp)
335 # endif
336 # ifndef this_cpu_read_2
337 # define this_cpu_read_2(pcp) _this_cpu_generic_read(pcp)
338 # endif
339 # ifndef this_cpu_read_4
340 # define this_cpu_read_4(pcp) _this_cpu_generic_read(pcp)
341 # endif
342 # ifndef this_cpu_read_8
343 # define this_cpu_read_8(pcp) _this_cpu_generic_read(pcp)
344 # endif
345 # define this_cpu_read(pcp) __pcpu_size_call_return(this_cpu_read_, (pcp))
346 #endif
348 #define _this_cpu_generic_to_op(pcp, val, op) \
349 do { \
350 preempt_disable(); \
351 *__this_cpu_ptr(&(pcp)) op val; \
352 preempt_enable(); \
353 } while (0)
355 #ifndef this_cpu_write
356 # ifndef this_cpu_write_1
357 # define this_cpu_write_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), =)
358 # endif
359 # ifndef this_cpu_write_2
360 # define this_cpu_write_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), =)
361 # endif
362 # ifndef this_cpu_write_4
363 # define this_cpu_write_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), =)
364 # endif
365 # ifndef this_cpu_write_8
366 # define this_cpu_write_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), =)
367 # endif
368 # define this_cpu_write(pcp, val) __pcpu_size_call(this_cpu_write_, (pcp), (val))
369 #endif
371 #ifndef this_cpu_add
372 # ifndef this_cpu_add_1
373 # define this_cpu_add_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=)
374 # endif
375 # ifndef this_cpu_add_2
376 # define this_cpu_add_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=)
377 # endif
378 # ifndef this_cpu_add_4
379 # define this_cpu_add_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=)
380 # endif
381 # ifndef this_cpu_add_8
382 # define this_cpu_add_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=)
383 # endif
384 # define this_cpu_add(pcp, val) __pcpu_size_call(this_cpu_add_, (pcp), (val))
385 #endif
387 #ifndef this_cpu_sub
388 # define this_cpu_sub(pcp, val) this_cpu_add((pcp), -(val))
389 #endif
391 #ifndef this_cpu_inc
392 # define this_cpu_inc(pcp) this_cpu_add((pcp), 1)
393 #endif
395 #ifndef this_cpu_dec
396 # define this_cpu_dec(pcp) this_cpu_sub((pcp), 1)
397 #endif
399 #ifndef this_cpu_and
400 # ifndef this_cpu_and_1
401 # define this_cpu_and_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=)
402 # endif
403 # ifndef this_cpu_and_2
404 # define this_cpu_and_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=)
405 # endif
406 # ifndef this_cpu_and_4
407 # define this_cpu_and_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=)
408 # endif
409 # ifndef this_cpu_and_8
410 # define this_cpu_and_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=)
411 # endif
412 # define this_cpu_and(pcp, val) __pcpu_size_call(this_cpu_and_, (pcp), (val))
413 #endif
415 #ifndef this_cpu_or
416 # ifndef this_cpu_or_1
417 # define this_cpu_or_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=)
418 # endif
419 # ifndef this_cpu_or_2
420 # define this_cpu_or_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=)
421 # endif
422 # ifndef this_cpu_or_4
423 # define this_cpu_or_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=)
424 # endif
425 # ifndef this_cpu_or_8
426 # define this_cpu_or_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=)
427 # endif
428 # define this_cpu_or(pcp, val) __pcpu_size_call(this_cpu_or_, (pcp), (val))
429 #endif
431 #ifndef this_cpu_xor
432 # ifndef this_cpu_xor_1
433 # define this_cpu_xor_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=)
434 # endif
435 # ifndef this_cpu_xor_2
436 # define this_cpu_xor_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=)
437 # endif
438 # ifndef this_cpu_xor_4
439 # define this_cpu_xor_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=)
440 # endif
441 # ifndef this_cpu_xor_8
442 # define this_cpu_xor_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=)
443 # endif
444 # define this_cpu_xor(pcp, val) __pcpu_size_call(this_cpu_or_, (pcp), (val))
445 #endif
447 #define _this_cpu_generic_add_return(pcp, val) \
448 ({ \
449 typeof(pcp) ret__; \
450 preempt_disable(); \
451 __this_cpu_add(pcp, val); \
452 ret__ = __this_cpu_read(pcp); \
453 preempt_enable(); \
454 ret__; \
457 #ifndef this_cpu_add_return
458 # ifndef this_cpu_add_return_1
459 # define this_cpu_add_return_1(pcp, val) _this_cpu_generic_add_return(pcp, val)
460 # endif
461 # ifndef this_cpu_add_return_2
462 # define this_cpu_add_return_2(pcp, val) _this_cpu_generic_add_return(pcp, val)
463 # endif
464 # ifndef this_cpu_add_return_4
465 # define this_cpu_add_return_4(pcp, val) _this_cpu_generic_add_return(pcp, val)
466 # endif
467 # ifndef this_cpu_add_return_8
468 # define this_cpu_add_return_8(pcp, val) _this_cpu_generic_add_return(pcp, val)
469 # endif
470 # define this_cpu_add_return(pcp, val) __pcpu_size_call_return2(this_cpu_add_return_, pcp, val)
471 #endif
473 #define this_cpu_sub_return(pcp, val) this_cpu_add_return(pcp, -(val))
474 #define this_cpu_inc_return(pcp) this_cpu_add_return(pcp, 1)
475 #define this_cpu_dec_return(pcp) this_cpu_add_return(pcp, -1)
477 #define _this_cpu_generic_xchg(pcp, nval) \
478 ({ typeof(pcp) ret__; \
479 preempt_disable(); \
480 ret__ = __this_cpu_read(pcp); \
481 __this_cpu_write(pcp, nval); \
482 preempt_enable(); \
483 ret__; \
486 #ifndef this_cpu_xchg
487 # ifndef this_cpu_xchg_1
488 # define this_cpu_xchg_1(pcp, nval) _this_cpu_generic_xchg(pcp, nval)
489 # endif
490 # ifndef this_cpu_xchg_2
491 # define this_cpu_xchg_2(pcp, nval) _this_cpu_generic_xchg(pcp, nval)
492 # endif
493 # ifndef this_cpu_xchg_4
494 # define this_cpu_xchg_4(pcp, nval) _this_cpu_generic_xchg(pcp, nval)
495 # endif
496 # ifndef this_cpu_xchg_8
497 # define this_cpu_xchg_8(pcp, nval) _this_cpu_generic_xchg(pcp, nval)
498 # endif
499 # define this_cpu_xchg(pcp, nval) \
500 __pcpu_size_call_return2(this_cpu_xchg_, (pcp), nval)
501 #endif
503 #define _this_cpu_generic_cmpxchg(pcp, oval, nval) \
504 ({ typeof(pcp) ret__; \
505 preempt_disable(); \
506 ret__ = __this_cpu_read(pcp); \
507 if (ret__ == (oval)) \
508 __this_cpu_write(pcp, nval); \
509 preempt_enable(); \
510 ret__; \
513 #ifndef this_cpu_cmpxchg
514 # ifndef this_cpu_cmpxchg_1
515 # define this_cpu_cmpxchg_1(pcp, oval, nval) _this_cpu_generic_cmpxchg(pcp, oval, nval)
516 # endif
517 # ifndef this_cpu_cmpxchg_2
518 # define this_cpu_cmpxchg_2(pcp, oval, nval) _this_cpu_generic_cmpxchg(pcp, oval, nval)
519 # endif
520 # ifndef this_cpu_cmpxchg_4
521 # define this_cpu_cmpxchg_4(pcp, oval, nval) _this_cpu_generic_cmpxchg(pcp, oval, nval)
522 # endif
523 # ifndef this_cpu_cmpxchg_8
524 # define this_cpu_cmpxchg_8(pcp, oval, nval) _this_cpu_generic_cmpxchg(pcp, oval, nval)
525 # endif
526 # define this_cpu_cmpxchg(pcp, oval, nval) \
527 __pcpu_size_call_return2(this_cpu_cmpxchg_, pcp, oval, nval)
528 #endif
531 * cmpxchg_double replaces two adjacent scalars at once. The first
532 * two parameters are per cpu variables which have to be of the same
533 * size. A truth value is returned to indicate success or failure
534 * (since a double register result is difficult to handle). There is
535 * very limited hardware support for these operations, so only certain
536 * sizes may work.
538 #define _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
539 ({ \
540 int ret__; \
541 preempt_disable(); \
542 ret__ = __this_cpu_generic_cmpxchg_double(pcp1, pcp2, \
543 oval1, oval2, nval1, nval2); \
544 preempt_enable(); \
545 ret__; \
548 #ifndef this_cpu_cmpxchg_double
549 # ifndef this_cpu_cmpxchg_double_1
550 # define this_cpu_cmpxchg_double_1(pcp1, pcp2, oval1, oval2, nval1, nval2) \
551 _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
552 # endif
553 # ifndef this_cpu_cmpxchg_double_2
554 # define this_cpu_cmpxchg_double_2(pcp1, pcp2, oval1, oval2, nval1, nval2) \
555 _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
556 # endif
557 # ifndef this_cpu_cmpxchg_double_4
558 # define this_cpu_cmpxchg_double_4(pcp1, pcp2, oval1, oval2, nval1, nval2) \
559 _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
560 # endif
561 # ifndef this_cpu_cmpxchg_double_8
562 # define this_cpu_cmpxchg_double_8(pcp1, pcp2, oval1, oval2, nval1, nval2) \
563 _this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
564 # endif
565 # define this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
566 __pcpu_double_call_return_bool(this_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
567 #endif
570 * Generic percpu operations that do not require preemption handling.
571 * Either we do not care about races or the caller has the
572 * responsibility of handling preemptions issues. Arch code can still
573 * override these instructions since the arch per cpu code may be more
574 * efficient and may actually get race freeness for free (that is the
575 * case for x86 for example).
577 * If there is no other protection through preempt disable and/or
578 * disabling interupts then one of these RMW operations can show unexpected
579 * behavior because the execution thread was rescheduled on another processor
580 * or an interrupt occurred and the same percpu variable was modified from
581 * the interrupt context.
583 #ifndef __this_cpu_read
584 # ifndef __this_cpu_read_1
585 # define __this_cpu_read_1(pcp) (*__this_cpu_ptr(&(pcp)))
586 # endif
587 # ifndef __this_cpu_read_2
588 # define __this_cpu_read_2(pcp) (*__this_cpu_ptr(&(pcp)))
589 # endif
590 # ifndef __this_cpu_read_4
591 # define __this_cpu_read_4(pcp) (*__this_cpu_ptr(&(pcp)))
592 # endif
593 # ifndef __this_cpu_read_8
594 # define __this_cpu_read_8(pcp) (*__this_cpu_ptr(&(pcp)))
595 # endif
596 # define __this_cpu_read(pcp) __pcpu_size_call_return(__this_cpu_read_, (pcp))
597 #endif
599 #define __this_cpu_generic_to_op(pcp, val, op) \
600 do { \
601 *__this_cpu_ptr(&(pcp)) op val; \
602 } while (0)
604 #ifndef __this_cpu_write
605 # ifndef __this_cpu_write_1
606 # define __this_cpu_write_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), =)
607 # endif
608 # ifndef __this_cpu_write_2
609 # define __this_cpu_write_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), =)
610 # endif
611 # ifndef __this_cpu_write_4
612 # define __this_cpu_write_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), =)
613 # endif
614 # ifndef __this_cpu_write_8
615 # define __this_cpu_write_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), =)
616 # endif
617 # define __this_cpu_write(pcp, val) __pcpu_size_call(__this_cpu_write_, (pcp), (val))
618 #endif
620 #ifndef __this_cpu_add
621 # ifndef __this_cpu_add_1
622 # define __this_cpu_add_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=)
623 # endif
624 # ifndef __this_cpu_add_2
625 # define __this_cpu_add_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=)
626 # endif
627 # ifndef __this_cpu_add_4
628 # define __this_cpu_add_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=)
629 # endif
630 # ifndef __this_cpu_add_8
631 # define __this_cpu_add_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=)
632 # endif
633 # define __this_cpu_add(pcp, val) __pcpu_size_call(__this_cpu_add_, (pcp), (val))
634 #endif
636 #ifndef __this_cpu_sub
637 # define __this_cpu_sub(pcp, val) __this_cpu_add((pcp), -(val))
638 #endif
640 #ifndef __this_cpu_inc
641 # define __this_cpu_inc(pcp) __this_cpu_add((pcp), 1)
642 #endif
644 #ifndef __this_cpu_dec
645 # define __this_cpu_dec(pcp) __this_cpu_sub((pcp), 1)
646 #endif
648 #ifndef __this_cpu_and
649 # ifndef __this_cpu_and_1
650 # define __this_cpu_and_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=)
651 # endif
652 # ifndef __this_cpu_and_2
653 # define __this_cpu_and_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=)
654 # endif
655 # ifndef __this_cpu_and_4
656 # define __this_cpu_and_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=)
657 # endif
658 # ifndef __this_cpu_and_8
659 # define __this_cpu_and_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=)
660 # endif
661 # define __this_cpu_and(pcp, val) __pcpu_size_call(__this_cpu_and_, (pcp), (val))
662 #endif
664 #ifndef __this_cpu_or
665 # ifndef __this_cpu_or_1
666 # define __this_cpu_or_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=)
667 # endif
668 # ifndef __this_cpu_or_2
669 # define __this_cpu_or_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=)
670 # endif
671 # ifndef __this_cpu_or_4
672 # define __this_cpu_or_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=)
673 # endif
674 # ifndef __this_cpu_or_8
675 # define __this_cpu_or_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=)
676 # endif
677 # define __this_cpu_or(pcp, val) __pcpu_size_call(__this_cpu_or_, (pcp), (val))
678 #endif
680 #ifndef __this_cpu_xor
681 # ifndef __this_cpu_xor_1
682 # define __this_cpu_xor_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=)
683 # endif
684 # ifndef __this_cpu_xor_2
685 # define __this_cpu_xor_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=)
686 # endif
687 # ifndef __this_cpu_xor_4
688 # define __this_cpu_xor_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=)
689 # endif
690 # ifndef __this_cpu_xor_8
691 # define __this_cpu_xor_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=)
692 # endif
693 # define __this_cpu_xor(pcp, val) __pcpu_size_call(__this_cpu_xor_, (pcp), (val))
694 #endif
696 #define __this_cpu_generic_add_return(pcp, val) \
697 ({ \
698 __this_cpu_add(pcp, val); \
699 __this_cpu_read(pcp); \
702 #ifndef __this_cpu_add_return
703 # ifndef __this_cpu_add_return_1
704 # define __this_cpu_add_return_1(pcp, val) __this_cpu_generic_add_return(pcp, val)
705 # endif
706 # ifndef __this_cpu_add_return_2
707 # define __this_cpu_add_return_2(pcp, val) __this_cpu_generic_add_return(pcp, val)
708 # endif
709 # ifndef __this_cpu_add_return_4
710 # define __this_cpu_add_return_4(pcp, val) __this_cpu_generic_add_return(pcp, val)
711 # endif
712 # ifndef __this_cpu_add_return_8
713 # define __this_cpu_add_return_8(pcp, val) __this_cpu_generic_add_return(pcp, val)
714 # endif
715 # define __this_cpu_add_return(pcp, val) __pcpu_size_call_return2(this_cpu_add_return_, pcp, val)
716 #endif
718 #define __this_cpu_sub_return(pcp, val) this_cpu_add_return(pcp, -(val))
719 #define __this_cpu_inc_return(pcp) this_cpu_add_return(pcp, 1)
720 #define __this_cpu_dec_return(pcp) this_cpu_add_return(pcp, -1)
722 #define __this_cpu_generic_xchg(pcp, nval) \
723 ({ typeof(pcp) ret__; \
724 ret__ = __this_cpu_read(pcp); \
725 __this_cpu_write(pcp, nval); \
726 ret__; \
729 #ifndef __this_cpu_xchg
730 # ifndef __this_cpu_xchg_1
731 # define __this_cpu_xchg_1(pcp, nval) __this_cpu_generic_xchg(pcp, nval)
732 # endif
733 # ifndef __this_cpu_xchg_2
734 # define __this_cpu_xchg_2(pcp, nval) __this_cpu_generic_xchg(pcp, nval)
735 # endif
736 # ifndef __this_cpu_xchg_4
737 # define __this_cpu_xchg_4(pcp, nval) __this_cpu_generic_xchg(pcp, nval)
738 # endif
739 # ifndef __this_cpu_xchg_8
740 # define __this_cpu_xchg_8(pcp, nval) __this_cpu_generic_xchg(pcp, nval)
741 # endif
742 # define __this_cpu_xchg(pcp, nval) \
743 __pcpu_size_call_return2(__this_cpu_xchg_, (pcp), nval)
744 #endif
746 #define __this_cpu_generic_cmpxchg(pcp, oval, nval) \
747 ({ \
748 typeof(pcp) ret__; \
749 ret__ = __this_cpu_read(pcp); \
750 if (ret__ == (oval)) \
751 __this_cpu_write(pcp, nval); \
752 ret__; \
755 #ifndef __this_cpu_cmpxchg
756 # ifndef __this_cpu_cmpxchg_1
757 # define __this_cpu_cmpxchg_1(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
758 # endif
759 # ifndef __this_cpu_cmpxchg_2
760 # define __this_cpu_cmpxchg_2(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
761 # endif
762 # ifndef __this_cpu_cmpxchg_4
763 # define __this_cpu_cmpxchg_4(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
764 # endif
765 # ifndef __this_cpu_cmpxchg_8
766 # define __this_cpu_cmpxchg_8(pcp, oval, nval) __this_cpu_generic_cmpxchg(pcp, oval, nval)
767 # endif
768 # define __this_cpu_cmpxchg(pcp, oval, nval) \
769 __pcpu_size_call_return2(__this_cpu_cmpxchg_, pcp, oval, nval)
770 #endif
772 #define __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
773 ({ \
774 int __ret = 0; \
775 if (__this_cpu_read(pcp1) == (oval1) && \
776 __this_cpu_read(pcp2) == (oval2)) { \
777 __this_cpu_write(pcp1, (nval1)); \
778 __this_cpu_write(pcp2, (nval2)); \
779 __ret = 1; \
781 (__ret); \
784 #ifndef __this_cpu_cmpxchg_double
785 # ifndef __this_cpu_cmpxchg_double_1
786 # define __this_cpu_cmpxchg_double_1(pcp1, pcp2, oval1, oval2, nval1, nval2) \
787 __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
788 # endif
789 # ifndef __this_cpu_cmpxchg_double_2
790 # define __this_cpu_cmpxchg_double_2(pcp1, pcp2, oval1, oval2, nval1, nval2) \
791 __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
792 # endif
793 # ifndef __this_cpu_cmpxchg_double_4
794 # define __this_cpu_cmpxchg_double_4(pcp1, pcp2, oval1, oval2, nval1, nval2) \
795 __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
796 # endif
797 # ifndef __this_cpu_cmpxchg_double_8
798 # define __this_cpu_cmpxchg_double_8(pcp1, pcp2, oval1, oval2, nval1, nval2) \
799 __this_cpu_generic_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
800 # endif
801 # define __this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
802 __pcpu_double_call_return_bool(__this_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
803 #endif
806 * IRQ safe versions of the per cpu RMW operations. Note that these operations
807 * are *not* safe against modification of the same variable from another
808 * processors (which one gets when using regular atomic operations)
809 * They are guaranteed to be atomic vs. local interrupts and
810 * preemption only.
812 #define irqsafe_cpu_generic_to_op(pcp, val, op) \
813 do { \
814 unsigned long flags; \
815 local_irq_save(flags); \
816 *__this_cpu_ptr(&(pcp)) op val; \
817 local_irq_restore(flags); \
818 } while (0)
820 #ifndef irqsafe_cpu_add
821 # ifndef irqsafe_cpu_add_1
822 # define irqsafe_cpu_add_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
823 # endif
824 # ifndef irqsafe_cpu_add_2
825 # define irqsafe_cpu_add_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
826 # endif
827 # ifndef irqsafe_cpu_add_4
828 # define irqsafe_cpu_add_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
829 # endif
830 # ifndef irqsafe_cpu_add_8
831 # define irqsafe_cpu_add_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
832 # endif
833 # define irqsafe_cpu_add(pcp, val) __pcpu_size_call(irqsafe_cpu_add_, (pcp), (val))
834 #endif
836 #ifndef irqsafe_cpu_sub
837 # define irqsafe_cpu_sub(pcp, val) irqsafe_cpu_add((pcp), -(val))
838 #endif
840 #ifndef irqsafe_cpu_inc
841 # define irqsafe_cpu_inc(pcp) irqsafe_cpu_add((pcp), 1)
842 #endif
844 #ifndef irqsafe_cpu_dec
845 # define irqsafe_cpu_dec(pcp) irqsafe_cpu_sub((pcp), 1)
846 #endif
848 #ifndef irqsafe_cpu_and
849 # ifndef irqsafe_cpu_and_1
850 # define irqsafe_cpu_and_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
851 # endif
852 # ifndef irqsafe_cpu_and_2
853 # define irqsafe_cpu_and_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
854 # endif
855 # ifndef irqsafe_cpu_and_4
856 # define irqsafe_cpu_and_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
857 # endif
858 # ifndef irqsafe_cpu_and_8
859 # define irqsafe_cpu_and_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
860 # endif
861 # define irqsafe_cpu_and(pcp, val) __pcpu_size_call(irqsafe_cpu_and_, (val))
862 #endif
864 #ifndef irqsafe_cpu_or
865 # ifndef irqsafe_cpu_or_1
866 # define irqsafe_cpu_or_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
867 # endif
868 # ifndef irqsafe_cpu_or_2
869 # define irqsafe_cpu_or_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
870 # endif
871 # ifndef irqsafe_cpu_or_4
872 # define irqsafe_cpu_or_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
873 # endif
874 # ifndef irqsafe_cpu_or_8
875 # define irqsafe_cpu_or_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
876 # endif
877 # define irqsafe_cpu_or(pcp, val) __pcpu_size_call(irqsafe_cpu_or_, (val))
878 #endif
880 #ifndef irqsafe_cpu_xor
881 # ifndef irqsafe_cpu_xor_1
882 # define irqsafe_cpu_xor_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
883 # endif
884 # ifndef irqsafe_cpu_xor_2
885 # define irqsafe_cpu_xor_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
886 # endif
887 # ifndef irqsafe_cpu_xor_4
888 # define irqsafe_cpu_xor_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
889 # endif
890 # ifndef irqsafe_cpu_xor_8
891 # define irqsafe_cpu_xor_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
892 # endif
893 # define irqsafe_cpu_xor(pcp, val) __pcpu_size_call(irqsafe_cpu_xor_, (val))
894 #endif
896 #define irqsafe_cpu_generic_cmpxchg(pcp, oval, nval) \
897 ({ \
898 typeof(pcp) ret__; \
899 unsigned long flags; \
900 local_irq_save(flags); \
901 ret__ = __this_cpu_read(pcp); \
902 if (ret__ == (oval)) \
903 __this_cpu_write(pcp, nval); \
904 local_irq_restore(flags); \
905 ret__; \
908 #ifndef irqsafe_cpu_cmpxchg
909 # ifndef irqsafe_cpu_cmpxchg_1
910 # define irqsafe_cpu_cmpxchg_1(pcp, oval, nval) irqsafe_cpu_generic_cmpxchg(pcp, oval, nval)
911 # endif
912 # ifndef irqsafe_cpu_cmpxchg_2
913 # define irqsafe_cpu_cmpxchg_2(pcp, oval, nval) irqsafe_cpu_generic_cmpxchg(pcp, oval, nval)
914 # endif
915 # ifndef irqsafe_cpu_cmpxchg_4
916 # define irqsafe_cpu_cmpxchg_4(pcp, oval, nval) irqsafe_cpu_generic_cmpxchg(pcp, oval, nval)
917 # endif
918 # ifndef irqsafe_cpu_cmpxchg_8
919 # define irqsafe_cpu_cmpxchg_8(pcp, oval, nval) irqsafe_cpu_generic_cmpxchg(pcp, oval, nval)
920 # endif
921 # define irqsafe_cpu_cmpxchg(pcp, oval, nval) \
922 __pcpu_size_call_return2(irqsafe_cpu_cmpxchg_, (pcp), oval, nval)
923 #endif
925 #define irqsafe_generic_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
926 ({ \
927 int ret__; \
928 unsigned long flags; \
929 local_irq_save(flags); \
930 ret__ = __this_cpu_generic_cmpxchg_double(pcp1, pcp2, \
931 oval1, oval2, nval1, nval2); \
932 local_irq_restore(flags); \
933 ret__; \
936 #ifndef irqsafe_cpu_cmpxchg_double
937 # ifndef irqsafe_cpu_cmpxchg_double_1
938 # define irqsafe_cpu_cmpxchg_double_1(pcp1, pcp2, oval1, oval2, nval1, nval2) \
939 irqsafe_generic_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
940 # endif
941 # ifndef irqsafe_cpu_cmpxchg_double_2
942 # define irqsafe_cpu_cmpxchg_double_2(pcp1, pcp2, oval1, oval2, nval1, nval2) \
943 irqsafe_generic_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
944 # endif
945 # ifndef irqsafe_cpu_cmpxchg_double_4
946 # define irqsafe_cpu_cmpxchg_double_4(pcp1, pcp2, oval1, oval2, nval1, nval2) \
947 irqsafe_generic_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
948 # endif
949 # ifndef irqsafe_cpu_cmpxchg_double_8
950 # define irqsafe_cpu_cmpxchg_double_8(pcp1, pcp2, oval1, oval2, nval1, nval2) \
951 irqsafe_generic_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
952 # endif
953 # define irqsafe_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2) \
954 __pcpu_double_call_return_bool(irqsafe_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
955 #endif
957 #endif /* __LINUX_PERCPU_H */